<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>表格</title>
</head>
<body>
    <table border="1" width="50%" align="center"> 
        <tr>
            <td>A1</td>
            <td>B1</td>
            <td>C1</td>
            <td>D1</td>
        </tr>
        <tr>
            <td>A2</td>
            <td>B2</td>
            <td>C2</td>
            <td rowspan="2">D2</td>
            <!-- <td>D2</td> -->
        </tr>
        <tr>
            <td>A3</td>
            <td>B3</td>
            
            <td>C3</td>
            <td>D3</td>
        </tr>
        <tr>
            <td>A4</td>
            <td>B4</td>
            <td colspan="2">C4</td>
            <!-- <td>C4</td>
            <td>D4</td> -->
        </tr>
      
    </table>
    
</body>
</html>